If you sold it, what would you do with the money and how does the return compare to what you get now (factoring in the amount of work/stress with each option)?

You could view a sponsor's history and look at the returns shown on their track record, but without context it's meaningless. 

They make money on every step of the process, and there's a lot of incentive for them to exaggerate what your returns will be.

In neighborhoods on the West like Old Brooklyn, Clark Fulton, and West Boulevard, I have seen properties yielding 10% and higher cash-on-cash returns.

A buddy of mine, who’s been an agent in the Phoenix market for nearly as long as I have, once had a client who stumbled into a 1031 that shot their returns through the roof because they snagged a property near one of those new tech corridors sprouting up.. from what I’ve heard, that corridor’s been buzzing with interest lately.What’s exciting right now is seeing how investors are leveraging 1031 exchanges to pivot into markets that are on fire.

LLCs require additional filing fees and tax returns and just complicate things.

Can you easily add a bedroom without making the flow feel weird (i.e. accessing one bedroom by going through another) or taking away from common area making them feel small?  

While $300K may not yield high returns in your market AND presumably limit you to smaller deals with less doors/units, the same amount could align you with a group of investors purchasing dozens of units elsewhere.

I tried in my market which is the 2nd biggest to New York, so pricing for ads was really high and the return was not great.

Today all these homes could be sold on the market for a good return since homes on Long Island has had big gains.